Investors in Japan might keep a close eye on sales of the homely horse mackerel as an early warning of any trouble ahead. The good news is that in the more confident Japan of 2013, tuna remains king. So says Mizuho Securities economist Kenta Ishizu, who believes he has found a leading indicat…

More:
Sushi’s Abenomics wave: posh tuna in, plain mackerel out
